Axial behavior of RC column strengthened with laterally reinforced FRHPC jacket

Abstract

AbstractThis paper is aimed to examine the axial compression performance of reinforced concrete (RC) base column specimens strengthened by fiber‐reinforced high‐performance concrete (FRHPC) jackets using the enlarged cross‐section method. For this purpose, the axial compression performance test is performed on one un‐strengthened column and four strengthened columns to assess the effects of FRHPC jacket thickness, whether the jacket was configured with stirrup and the spacing of stirrup were considered. Based on the theory of confined concrete and the FRHPC principal structure relationship, a theoretical calculation model is also established to explore the axial load‐carrying capacity of the columns. The test results indicate that an increase of the cross‐sectional reinforcement of the FRHPC jacket can enhance the axial compression load capacity and ductility of the columns. Furthermore, an increase in the FRHPC jacket thickness leads to the growth of the load capacity; however, there is no significant increase on the ground of its ductility. The addition of stirrup in the FRHPC jacket can improve both load capacity and ductility of the columns such that the smaller the spacing of the stirrup, the greater the increase of both load capacity and ductility. The predicted results by the proposed model are in good agreement with those of the tests.